1. Field of the Invention
A key signature actuator for a musical keyboard eases playing from musical compositions written with difficult key signatures without reprinting the music, by changing the keyboard fingering of the musical compositions.
A uniform pitch changer for a musical keyboard, without changing the keyboard fingering of a musical composition, changes each tone of the musical composition by the same musical interval.
2. Description of the Prior Art
The traditional way of writing Western music is to position musical notes on a set of parallel lines. In each octave, seven musical notes represent the seven tones of a basic diatonic scale, the other five tones of the twelve-tone scale being referred to the notes of the basic diatonic scale by means of sharp or flat symbols which serve as corrections to the basic diatonic notes. Thus a "chromatic" tone intermediate to the C and D tones is represented as C sharp or D flat.
Since the most commonly grouped tones in music are the seven tones of the diatonic scale, our traditional musical keyboard was structured so as to play the basic diatonic scale on its front digitals and the other five tones, which constitute the tonal pentatonic scale, on its back digitals. The notes of written keyboard music are normally interpreted as instructions to play particular digitals of the keyboard. The major mode of the diatonic scale, starting with a C note, is played on a C front digital. The succeeding D, E, F, G, A, B notes of the diatonic scale are played on the succeeding D, E, F, G, A, B front digitals. The notes of written music can thus be interpreted as instructions to play particular digitals of the keyboard, each front and back digital of the keyboard identified by a note in the written music and serving to identify that musical note. This arrangement had the original advantage that the most commonly grouped notes were played on the wide front digitals of the keyboard.
Since people come in all sizes and shapes there can be no universal agreement on exactly which are the best wave lengths for sound waves in the air, but people can agree much better on the relative pitches of sequentially sounded musical tones. Thus if a uniform pitch changer in a keyboard is used to raise all the tones sounded by all of its digitals same musical interval, since it does not affect the relative musical intervals between the tones of a musical composition, for example, it will be universally recognized after the uniform change of pitch as the same musical composition.
Many musical instruments contain uniform pitch changers, but many do not. For a tonal musical composition to sound its best and to be playable on all instruments, therefore, it is usually necessary to start the major mode of its diatonic scale on some note of the twelve-tone scale other than C. In written music this necessitates correction of one or more of the seven notes of the basic diatonic scale by means of a sharp or flat symbol. The composer finds it convenient to specify the basic diatonic note corrections by means of a key signature that is placed at the front of each line of written music. Key signatures greatly reduce the effort needed to write modern music in other keys than C, and to understand the written music.
In earlier times, a change in the overall output pitch of a musical composition meant that the composition was being played in a different musical key. But in modern times, with the wide use of uniform pitch changers, there is no longer a one-to-one correspondence between the overall pitch of a musical composition as sounded and the key in which the composition is written and played.
The note corrections in a key signature of written music require playing of the back digitals of a keyboard. This detracts from the previous virtue of the traditional keyboard, of providing wide front digitals for the most commonly played notes. Furthermore, the ordinary keyboard player has difficulty remembering and playing all the sharps and flats called for in the fourteen key signatures. Music publishers have reprinted some of the older music with easier key signatures, but the reprinted music usually does not sound as good as when it is played in its original key, and it is usually harder to sing.
It would be possible to reprint all music in the key of C for the benefit of musicians having uniform pitch changers, but many instruments in a band or orchestra do not have uniform pitch changers, so they must play from the music as originally written. Thus uniform pitch changers and the reprinting of music do not provide an adequate solution to the problem of difficult key signatures.
To alleviate these difficulties, a keyboard instrument can be provided with a device to automatically actuate the tone corrections specified in the key signature. Such a device, which I call a key signature actuator, was disclosed by Martin Phillips in 1886 (U.S. Pat. Nos. 354,733, 466,907, and 519,071). If, for example, the device was set for a key signature with one sharp, then the F front digital would sound not the F tone but the F sharp tone instead, as called out in the key signature. This century-old key signature actuator has not been widely used because of its mechanical complexity and expense.
As opposed to uniform pitch changers, most key signature actuators change the musical intervals between the tones sounded by a given sequence of digitals. For example, when the F front digital is made to sound the F sharp tone the interdigital musical interval between the E and F front digitals is changed from one semitone to two semitones, and the interdigital musical interval between the F and G front digitals is changed from two semitones to one semitone. A consequence of this difference between a key signature actuator and a uniform pitch changer is that key signature actuators are generally more difficult to construct, and they are not widely available.
Whereas the function of a uniform pitch changer is usually to change the overall pitch of the output music away from the pitch of the written music, the function of a key signature actuator is to ease playing from music written with difficult key signatures without rewriting the music.
A key signature actuator greatly reduces the mechanical difficulty of playing in other keys than C, because it changes the fingering of a musical composition; the most frequently occurring notes are again played on the wide front digitals of the keyboard. The mental difficulty of playing music is also reduced, because the musician can play the notes as they appear in the body of the written music, unmodified by its key signature. If key signature actuators were available commercially, then a musical composition could more generally be printed in the musical key in which it sounds best and is most easily sung. This better music could then be played by inexpert players on electronic musical instruments having key signature actuators. More expert musicians having acoustic instruments without key signature actuators could also play the better music. Improvements in key signature actuators are disclosed in my U.S. Pat. Nos. 3,986,422, 4,048,893, 4,640,173, and 4,750,399, and my copending application Ser. No. 166,464, filed 3-10-88, U.S. Pat. No. 4,821,619.
In modern musical practice it is common to have a musical keyboard and a sound generator in different places, the keyboard transmitting binary coded messages to the sound generator on a pair of wires. When a single digital of the keyboard is pressed, a "Note On" message is transmitted in binary code to the sound module, accompanied by a number which identifies the keyboard digital and the note in written music that it is playing. This message tells the sound module to generate a musical tone of the proper pitch. When the keyboard digital is released, a "Note Off" message, accompanied by the note and digital identifying number, can be transmitted to the sound module, and the musical tone will be discontinued. Musical instrument manufacturers have established an international standard for such communication, called "Musical Instrument Digital Interface" (MIDI).
My copending patent application Ser. No. 255,751 discloses a new use for the MIDI interface whereby MIDI transmission to a sound generator is intercepted and the numbers changed in accordance with a selected key signature, the pitch numbers transmitted to the sound generator resulting in automatic actuation of the key signature. In any musical key the key signature actuator allows all of the tonal diatonic notes to be played on the front digitals of a musical keyboard, and the non-diatonic notes to be played on the back digitals. The keyboard requires two extra back digitals per octave span.